Study On The Performance Of Steel Structure Assembled Joints

In recent years,due to the promotion of urbanization and the support of the relevant national policies,the development of the steel structure building has become an inevitable trend.And the fabricated steel structure with short construction period,less environmental pollution meets the green,innovative and efficient development concept.Based on this,the assembled joint is put forward in this paper.After the industrial production of all the components,they can be assembled by high-strength bolts at the construction site.The installation is easy and the building facade is beautiful.However,there is little research on this kind of connection form at home and abroad.Therefore,it is very important to study the mechanical properties of the assembled jointFirstly,the model of assembled joint and rigid joint with same beam column size is established using ABAQUS software.The failure process of the specimens is analyzed.Initial stiffness,bearing capacity,hysteretic behavior and energy dissipation capacity of assembly joint in the side column and the middle column are summarized.To study the influence of different parameters on the mechanical properties of assembly joints,8 kinds of assembled joints with different sizes are designed according to the thickness of outer sleeve and beam,the number of bolts and the length of the sleeve.Finally,the overall mechanical properties of two steel frames with assembled joints and pure rigid joints are analyzed under monotonic loading.Furthermore,the bolt internal force and sleeve connection is calculated and checked according to theory formulas.Research shows:(1)With the increase of the sleeve length,the stress of the node will increase,and the bearing capacity as well as energy dissipation capacity becomes better.However,if the length of the sleeve increases incessantly,the failure form is converted to the rib buckling failure.The bearing capacity of the specimen reduces and the energy dissipation capacity become weak.Therefore,it is suggested that the sleeve shouldn’t be too long and the plastic hinge can be produced at the beam for good mechanical properties.(2)When the beam is 4mm thinner than the sleeve,the beam stiffness is lower,the specimen is damaged earlier,the bending capacity is low and the energy dissipation capacity is weak.Keep the thickness of the sleeve constant and increase the thickness of the beam,the bearing capacity of thespecimen is obviously improved.The equivalent viscous damping coefficient and the kinetic energy consumption increase.(3)It is suggested that the sleeve is 2mm thicker than beam.The ultimate bearing capacity of assembled joint is 30% higher than that of the pure steel rigid joint with same beam column section size.The equivalent viscous damping coefficient is more than 0.4.And the assembled joints is also with full hysteresis,good energy dissipation and excellent seismic performance.(4)With the reduce of the bolts number,the flexural strength,equivalent viscous damping coefficient and the energy dissipation also decrease.